1. Technical Field
The present invention is directed toward rivet joints, and more particularly toward window mechanism pivot joints having minimal axial free play.
2. Background Art
Pivotal connections between two members are common, including particularly in window opening mechanisms which have a number of pivotal connections between links. These connections most often consist of a conventional rivet having a flat head and a malleable tubular body or shank extending through cylindrical openings in the connected links. The malleable body is compressed to form a second head, securing the links between the two heads.
Further, such pivotal connections are commonly formed with a rivet shank having two sections and a shoulder therebetween, with the section adjacent the first head having the greater diameter and being slightly greater in length than its associated link is thick. The shoulder abuts the other link to prevent it from being frictionally bound against the first link during the formation of the second rivet head in assembly. Such binding would undesirably restrict the free pivoting of the links during operation.
Unfortunately, where the length of the rivet shank section is not precisely formed relative to the link thickness, there is an undesirable axial free play between the links. Such free play can cause excessive wear on the links and the components connected to the links. Excessive axial free play can also lead to jamming of the mechanism at the pivotal connection. Such jamming is obviously particularly undesirable when it results in window hinges or operators being stuck open. Further, inasmuch as pivoting at the joint stresses the pivotal connection, initial axial free play is naturally exacerbated and can eventually result in complete failure of the pivotal connection. Still further, the loose feel resulting from initial free play can cause potential users to believe that the mechanism is poorly constructed.
Some methods have been devised to minimize this axial free play, but they require either special tools or two separate operations significantly increasing the cost of manufacturing the connections. Thus, manufacturers have heretofore been forced to choose between either accepting undesirable axial free play or eliminating the axial free play by costly methods placing them at a competitive disadvantage.
The present invention is directed toward overcoming one or more of the problems set forth above.